Embodiments of the present invention relate to a socket for mounting an integrated circuit package on a circuit board. In particular, the present invention relates to a system and method for inserting an integrated circuit package on a circuit board without applying a damaging force to the pins.
Circuit boards often contain integrated circuit (IC) packages, such as central processing units or other integrated circuit devices, that are mounted on the board. The integrated circuit package generally has a substrate upon which a silicon chip is supported and a series of metal pins that extend from the underside of the integrated circuit package. The pins, which may be arranged in one or more rows, are used to conduct electric current between the chip and the circuit board. The integrated circuit package is not typically mounted directly to the board, but rather is directly mounted on a socket which is itself connected to the board. The socket may contain a base that is attached to the board as well as contacts which create electrical connections with the pins of the integrated circuit package. Each contact may contain an opening that is spaced to allow a pin to fit tightly within. When an integrated circuit package is being connected to the board, a relatively significant force is generally applied to the pins so that they tightly engage the contacts as is desired for a reliable electrical connection.
The pins of an integrated circuit package are often delicate and easily bent. If the pins are damaged, the integrated circuit package may not sit correctly and may malfunction. Damage to the pins may render an expensive integrated circuit chip unusable. A circuit board manufacturer may employ quality controls to ensure that the pins are not damaged when an integrated circuit package is inserted into a socket. However, an end-user may often desire to remove an old integrated circuit package from a circuit board and insert a new integrated circuit package. For example, a user may wish to insert a new central processing unit (i.e., an upgrade) onto the motherboard of an existing personal computer. Because end-users may not have the tools and/or skills to insert and remove an integrated circuit package without damaging pins, sockets have been developed to enable an integrated circuit package to be easily removed or inserted while still ensuring that the device securely fits into the socket. These sockets, which are often referred to as xe2x80x9czero insertion forcexe2x80x9d (ZIF) sockets, employ a mechanism to control the application of the force used to engage the pins with the contacts.
In addition to a base and electrically-conductive contacts, conventional ZIF sockets typically also have a sliding cover on top of the base, a bar which is coupled to the cover, and a lever arm (or actuator arm) that is coupled to the sliding bar. In such ZIF sockets the integrated circuit package is mounted on top of the socket cover, with the pins of the integrated circuit package protruding through the holes in the cover. The cover guides the pins when the chip is being placed on the socket. In addition, the cover is used to apply horizontal force directly to the pins in order to actuate the pins onto the electrical contacts in the socket base. Before inserting an integrated circuit package into such a ZIF socket, the lever arm is raised, thus sliding the sliding arm and cover into an xe2x80x9copenxe2x80x9d position. The pins of the integrated circuit package may then be inserted into the holes in the cover. At this point, the pins would generally not be engaged with the contacts. To engage the pins, the actuator arm is closed, causing the sliding bar and cover to slide horizontally across the base of the socket (i.e., in the same general direction as the plane of the circuit board). When the cover slides, it directly pushes against the pins so that the pins are engaged with the contacts. To remove the integrated circuit package, the lever arm is opened so that the pins may be disengaged from the contacts and the integrated circuit package may be removed without any damaging forces being asserted to the pins.